1. Field of the Invention
The present invention relates to a structure for preventing a flame of an alternator for a vehicle, and in particular to a structure for preventing a flame of an alternator for a vehicle which is capable of preventing a flame due to a spark from being moved to the outside and discharging dust formed due to a friction of a brush.
2. Description of the Background Art
Generally, an alternator(alternating current generator) for a vehicle is formed of a stator, a rotor and a diode, When an agitation switch is turned on, a current of a battery is applied to a rotor coil through a voltage regulator for thereby generating a magnetic force line. When an engine is started, and a rotor is rotated, a power is generated in the stator coil for thereby generating a 3-phase alternating current. The thusly generated 3-phase alternating current is rectified by the diode. When the voltage of the terminal B is higher than the voltage of the battery, the battery is charged, and the current is applied to each load.
As shown in FIG. 1, the alternator includes a driving shaft 2 provided in a front housing 1 sealed using a rear cover 4 and having a slip ring 3, and a brush assembly 5 installed at one side of the driving shaft 2. The brush assembly 5 includes a brush 6 contacting with the slip ring 3, a brush holder 7 for receiving the brush 6, and a sealing member 10 disposed between the front housing 1 and the rear cover 4 for sealing the brush holder 7.
The brush holder 7 includes an extended portion 7b. A flowing path K is formed toward an outlet hole 7a of the extended portion 7b and the rear cover 4 based on an inlet hole 10a, and a net-shaped wire net 20 is formed in the outlet hole 7a. 
Therefore, an external air is flown to the inside of the front housing 1 based on the flowing path K formed by the brush holder 7 and the sealing member 10. A fine dust of the brush 6 formed due to a friction with the slip ring 3 based on the rotation of the driving shaft 2 is discharged toward the outlet hole 7a through the flowing path K.
In a state that a certain gas is fully filled in an engine room for a ship, a flame generated by a spark of the brush 6 and the slip ring 3 is blocked by the wire net 20 provided in the outlet hole 7a of the brush holder 7 for thereby preventing the flame from being charged to the outside. In addition, the flame is not transferred to the engine room filled with the gas. Since the flowing path K is formed by the brush holder 7 and the sealing member 10, in order to form the flowing path K, the structure of the brush holder 7 must be changed, so that the fabrication process is complicated, and the cost thereof is increased.
Accordingly, it is an object of the present invention to provide a structure for preventing a flame of an alternator for a vehicle which is capable of preventing an explosion due to the spark and a flame from being transferred to the engine room by forming the flowing path and discharging a fine dust of the brush without changing the structure of the brush assembly formed of a holder cap and a brush holder. Which are detachable.
In order to achieve the above object, there is provided a structure for preventing a flame of an alternator for a vehicle in which the brush assembly includes a brush holder receiving a brush and a holder cap detachably engaged to the brush holder, and a first flow way is formed in an upper portion of the brush holder and the holder cap for passing through the air flown through an inlet hole formed in a sealing member, and a second flow way is formed at a side portion of the brush holder and the holder cap in an alternator for a vehicle which is formed of a brush assembly having a brush contacting with a slip ring inserted onto one end of a driving shaft installed in a front housing and a sealing member provided at a lower portion of the brush assembly, a flame prevention structure for an alternator of a vehicle.